This invention relates to a top cap or cover of fiberboard or other rigid but foldable material to provide outdoor protection from the elements for metal or other material which is otherwise exposed to rain or other precipitation or to mechanical injury. More particularly, this invention relates to an octagonal cover protection for generally round objects such as coiled sheet aluminum or steel. The octagonal shape of the cover allows the shape of the cover to approximate the shape of a circular or coiled object which is covered.